Dehydration kinetics of sodium perborate tetrahydrate to monohydrate in a fluidized-bed drier

Dehydration kinetics of sodium perborate tetrahydrate to monohydrate is inv estigated at four different temperatures between 314.7 and 331 K in a contr olled fluidized-bed drier. During the dehydration, no thermal decomposition of sodium perborate to sodium metaborate is observed. First-order kinetic behavior in this conversion is proved and the activation energy for dehydra tion is calculated as 80.18 kJ/mol. Effect of temperature on the bulk densi ty of the product is given and compared with theoretical calculations. Chan ge in the bulk density is attributed to two different competitive effects, one is shrinking and the other is puffing. Bulk density of the product can be adjusted by controlling these two parameters. (C) 1998 Elsevier Science Ltd. All rights reserved.